A catharsis-seeking blogger at “Vast Left-Wing Conspiracy” is so fed up with President Barack Obama’s tack to the center that he’s hoping other disaffected Democrats will digitally dog-pile on POTUS during “Grumble About Obama Day.”

The nonbinding, virtual venting session — “It’s this one, no-fault day,” Vast Left explained — has been set for May 2. The only requirement is letting “44” know just how disappointed liberals are in what the blogger characterizes as the administration’s total about-face on progressive policies.

“CHANGE turned out to be … reaching across the aisle to this party we were already sick of,” the self-proclaimed lifelong Democrat told HOH.

Re-electing Obama, Vast Left fears, would only cement the raft of “terrible, conservative, cruel” initiatives instituted in his first term, including what he considers to be untenable overreaches on the so-called global war on terror, the eradication of core civil rights and abandonment of fiscal responsibility.

Those not yet ready to jump ship can at least shake their electronic fists next week but should prepare to hold their noses come November.

“I think my days of standing in solidarity with a single party are done,” Vast Left said, hinting that supporting third-party candidates might be the way to go in the future.